WO2021255852A1 - Cutting insert and method for manufacturing cutting insert - Google Patents

Cutting insert and method for manufacturing cutting insert Download PDF

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Publication number
WO2021255852A1
WO2021255852A1 PCT/JP2020/023736 JP2020023736W WO2021255852A1 WO 2021255852 A1 WO2021255852 A1 WO 2021255852A1 JP 2020023736 W JP2020023736 W JP 2020023736W WO 2021255852 A1 WO2021255852 A1 WO 2021255852A1
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WO
WIPO (PCT)
Prior art keywords
base material
thickness direction
cutting edge
divided pieces
cutting insert
Prior art date
Application number
PCT/JP2020/023736
Other languages
French (fr)
Japanese (ja)
Inventor
岳 原田
悟 平尾
育朗 糸原
Original Assignee
住友電工ハードメタル株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友電工ハードメタル株式会社 filed Critical 住友電工ハードメタル株式会社
Priority to CN202080102096.6A priority Critical patent/CN115835938A/en
Priority to JP2022531164A priority patent/JP7419531B2/en
Priority to PCT/JP2020/023736 priority patent/WO2021255852A1/en
Priority to EP20940838.4A priority patent/EP4169663B1/en
Priority to US18/010,226 priority patent/US20230321732A1/en
Publication of WO2021255852A1 publication Critical patent/WO2021255852A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/28—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • B23B27/16—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped
    • B23B27/1603—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped with specially shaped plate-like exchangeable cutting inserts, e.g. chip-breaking groove
    • B23B27/1611—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped with specially shaped plate-like exchangeable cutting inserts, e.g. chip-breaking groove characterised by having a special shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • B23B27/141—Specially shaped plate-like cutting inserts, i.e. length greater or equal to width, width greater than or equal to thickness
    • B23B27/145—Specially shaped plate-like cutting inserts, i.e. length greater or equal to width, width greater than or equal to thickness characterised by having a special shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • B23B27/18—Cutting tools of which the bits or tips or cutting inserts are of special material with cutting bits or tips or cutting inserts rigidly mounted, e.g. by brazing
    • B23B27/20—Cutting tools of which the bits or tips or cutting inserts are of special material with cutting bits or tips or cutting inserts rigidly mounted, e.g. by brazing with diamond bits or cutting inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/16—Milling-cutters characterised by physical features other than shape
    • B23C5/20—Milling-cutters characterised by physical features other than shape with removable cutter bits or teeth or cutting inserts
    • B23C5/202—Plate-like cutting inserts with special form
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/0008—Soldering, e.g. brazing, or unsoldering specially adapted for particular articles or work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/008—Soldering within a furnace
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
    • B23K31/02—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to soldering or welding
    • B23K31/025—Connecting cutting edges or the like to tools; Attaching reinforcements to workpieces, e.g. wear-resisting zones to tableware
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2200/00—Details of cutting inserts
    • B23B2200/04—Overall shape
    • B23B2200/0471—Square
    • B23B2200/0476—Square rounded
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2226/00—Materials of tools or workpieces not comprising a metal
    • B23B2226/12—Boron nitride
    • B23B2226/125—Boron nitride cubic [CBN]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2226/00—Materials of tools or workpieces not comprising a metal
    • B23B2226/31—Diamond
    • B23B2226/315—Diamond polycrystalline [PCD]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2240/00—Details of connections of tools or workpieces
    • B23B2240/08—Brazed connections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2200/00—Details of milling cutting inserts
    • B23C2200/04—Overall shape
    • B23C2200/0455—Square
    • B23C2200/0461—Square rounded
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2226/00—Materials of tools or workpieces not comprising a metal
    • B23C2226/12—Boron nitride
    • B23C2226/125—Boron nitride cubic [CBN]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2226/00—Materials of tools or workpieces not comprising a metal
    • B23C2226/31—Diamond
    • B23C2226/315—Diamond polycrystalline [PCD]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2240/00—Details of connections of tools or workpieces
    • B23C2240/08—Brazed connections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
    • B23K2103/52—Ceramics

Definitions

  • This disclosure relates to a cutting insert and a method for manufacturing the cutting insert.
  • Patent Document 1 Japanese Patent Publication No. 60-53404 describes a cutting tool.
  • the cutting tool described in Patent Document 1 has a base metal and a plurality of hard sintered body pieces. A plurality of sintered body pieces are joined to a base metal.
  • the cutting insert of the present disclosure includes a base material and a cutting edge tip.
  • the base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material.
  • the upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction.
  • the upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction.
  • a through hole is formed in the protrusion so as to penetrate the base material along the thickness direction.
  • the protrusion has a side surface that is continuous with the upper surface.
  • the side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction.
  • the curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum.
  • the cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape.
  • the cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides.
  • Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides.
  • Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end.
  • Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end.
  • the first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. ..
  • Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
  • FIG. 1 is a perspective view of the cutting insert 100.
  • FIG. 2 is a perspective view of the base material 10.
  • FIG. 3 is a plan view of the base material 10.
  • FIG. 4A is a plan view of the divided piece 21.
  • FIG. 4B is a bottom view of the divided piece 21.
  • FIG. 5 is a plan view of the cutting insert 100.
  • FIG. 6 is a process diagram showing a method of manufacturing the cutting insert 100.
  • FIG. 7 is an exploded perspective view of the cutting insert 100A.
  • FIG. 8 is a perspective view of the cutting insert 100B.
  • FIG. 9 is a schematic diagram for explaining the effect of the cutting insert 100.
  • the present disclosure provides a cutting insert and a method for manufacturing a cutting insert, which can suppress the formation of a gap between each of a plurality of divided pieces constituting the cutting edge tip.
  • the cutting insert according to the embodiment includes a base material and a cutting edge tip.
  • the base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material.
  • the upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction.
  • the upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction.
  • a through hole is formed in the protrusion so as to penetrate the base material along the thickness direction.
  • the protrusion has a side surface that is continuous with the upper surface.
  • the side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction.
  • the curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum.
  • the cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape.
  • the cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides.
  • Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides.
  • Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end.
  • Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end.
  • the first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. ..
  • Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
  • the cutting insert of (1) above it is possible to suppress the formation of a gap between each of the plurality of divided pieces constituting the cutting edge tip. Further, according to the cutting insert of the above (1), the amount of the material used for the cutting edge tip and the processing cost for the cutting edge tip can be reduced. Further, according to the cutting insert of (1) above, a larger portion of the cutting edge tip can be used as a cutting edge.
  • the curve may be composed of a plurality of partial arcs.
  • Each of the plurality of partial arcs may face each of the plurality of sides.
  • the distance between the corner of the protrusion and the center of the through hole may be greater than the distance between each of the plurality of vertices and the center. In this case, the amount of material used for the cutting edge tip can be further reduced.
  • the cutting edge tip may be formed of a cubic boron nitride sintered body or a polycrystalline diamond sintered body.
  • the method for manufacturing a cutting insert includes a step of preparing a base material and a cutting edge tip, and a step of brazing the cutting edge tip to the base material.
  • the base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material.
  • the upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction.
  • the upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction.
  • a through hole is formed in the protrusion so as to penetrate the base material along the thickness direction.
  • the protrusion has a side surface that is continuous with the upper surface.
  • the side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction.
  • the curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum.
  • the cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape.
  • the cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides.
  • Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides.
  • Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end.
  • Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end.
  • the first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. ..
  • Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
  • the method for manufacturing a cutting insert according to (4) above it is possible to suppress the formation of a gap between each of a plurality of divided pieces constituting the cutting edge tip. Further, according to the method for manufacturing a cutting insert according to the above (4), it is possible to reduce the amount of material used for the cutting edge tip and the processing cost for the cutting edge tip. Further, according to the method for manufacturing a cutting insert according to the above (4), a larger portion of the cutting edge tip can be used as a cutting edge.
  • cutting insert 100 (Structure of cutting insert according to embodiment)
  • cutting insert 100 the configuration of the cutting insert according to the embodiment
  • FIG. 1 is a perspective view of the cutting insert 100. As shown in FIG. 1, the cutting insert 100 has a base material 10 and a cutting edge tip 20.
  • the base material 10 is formed of, for example, a cemented carbide. However, the base material 10 may be formed of a material other than the cemented carbide.
  • FIG. 2 is a perspective view of the base material 10.
  • FIG. 3 is a plan view of the base material 10. As shown in FIGS. 2 and 3, the base material 10 has a bottom surface 10a and a top surface 10b in the thickness direction of the base material 10. The upper surface 10b is the opposite surface of the bottom surface 10a.
  • the base material 10 further has a side surface 10c. The side surface 10c is connected to the bottom surface 10a and the top surface 10b.
  • the upper surface 10b has a polygonal shape in a plan view (hereinafter, simply referred to as "plan view”) viewed along the thickness direction of the base material 10.
  • This polygon shape does not have to be a mathematically exact polygon shape.
  • the base material 10 has a polygonal shape in a plan view.
  • the upper surface 10b has a quadrangular shape (square shape).
  • the above polygonal shape (upper surface 10b) is composed of a first side 10ba, a second side 10bb, a third side 10bc, and a fourth side 10bd.
  • the first side 10ba is connected to the third side 10bc at one end, and is connected to the fourth side 10b at the other end.
  • the second side 10bb is connected to the fourth side 10bd at one end, and is connected to the third side 10bb at the other end.
  • a protrusion 11 is provided on the upper surface 10b.
  • the protruding portion 11 projects toward the side opposite to the bottom surface 10a along the thickness direction of the base material 10. That is, there is a step between the protrusion 11 and the upper surface 10b.
  • the protrusion 11 is located at the center of the upper surface 10b in a plan view.
  • the protruding portion 11 has an upper surface 11a and a side surface 11b.
  • the upper surface 11a is parallel to, for example, the upper surface 10b (bottom surface 10a).
  • the side surface 11b is connected to the upper surface 11a and the upper surface 10b.
  • a through hole 30 is formed in the protruding portion 11 (upper surface 11a).
  • the through hole 30 penetrates the base material 10 (cutting insert 100) along the thickness direction of the base material 10.
  • the through hole 30 is located at the center of the protrusion 11 (center of the upper surface 11a) in a plan view.
  • the through hole 30 has a circular shape in a plan view.
  • the center of the through hole 30 in a plan view is defined as the center C.
  • the clamp screw is passed through the through hole 30.
  • the cutting insert 100 is fastened and fixed to the holder (not shown).
  • the side surface 11b is composed of a curved line that is convex toward the side opposite to the through hole 30. More specifically, the side surface 11b is composed of a first surface 11ba, a second surface 11bb, a third surface 11bc, and a fourth surface 11bd. The first surface 11ba to the fourth surface 11bd face the first side 10ba to the fourth side 10b, respectively.
  • the first surface 11ba to the fourth surface 11bd are composed of partial arcs. That is, the side surface 11b is composed of a number of partial arcs equal to the number of sides constituting the upper surface 10b in a plan view. The radius of curvature of these partial arcs is larger than the radius of the circle indicating the through hole 30 in a plan view.
  • the curve showing the side surface 11b in a plan view has a plurality of vertices at positions where the distance from each side constituting the upper surface 10b is minimized.
  • the vertex of the partial arc indicating the first surface 11ba is the vertex P1
  • the vertex of the partial arc indicating the second surface 11bb is the vertex P2
  • the vertex of the partial arc indicating the third surface 11bc is the vertex P3.
  • the apex of the partial arc indicating the fourth surface 11db is defined as the apex P4.
  • the distance between the corner of the protrusion 11 and the center C in a plan view is defined as the distance DIS1.
  • the distance between the apex P1 (vertex P2, apex P3, apex P4) and the center C in the plan view is defined as the distance DIS2.
  • the distance DIS1 is larger than, for example, the distance DIS2.
  • the cutting edge tip 20 is formed of, for example, a cubic boron nitride sintered body.
  • the cubic boron nitride particle sintered body is a sintered body containing cubic boron nitride particles and a binder such as cobalt.
  • the cutting edge tip 20 may be formed of a polycrystalline diamond sintered body.
  • the polycrystalline diamond sintered body is a sintered body containing diamond particles and a binder such as cobalt.
  • the cutting edge tip 20 may be formed of a material having a hardness higher than that of the base material 10 other than the cubic boron nitride sintered body and the polycrystalline diamond sintered body.
  • the cutting edge tip 20 is divided into a plurality of divided pieces 21 in a plan view.
  • the number of the plurality of divided pieces 21 is four. That is, the cutting edge tip 20 is divided into a number of divided pieces 21 equal to the number of sides constituting the upper surface 10b.
  • Each of the plurality of divided pieces 21 has, for example, the same shape. In the following, these four divided pieces may be referred to as a divided piece 21a, a divided piece 21b, a divided piece 21c, and a divided piece 21d, respectively.
  • the cutting edge tip 20 is arranged on the upper surface 10b so as to surround the periphery of the protrusion 11 in an annular shape. More specifically, in the cutting edge tip 20, the longitudinal direction of the split piece 21a is along the first side 10ba, the longitudinal direction of the split piece 21b is along the second side 10bb, and the longitudinal direction of the split piece 21c is the third side 10bc.
  • the divided pieces 21d are arranged on the upper surface 10b so as to be along the fourth side 10bd (see FIG. 5).
  • FIG. 4A is a plan view of the divided piece 21.
  • FIG. 4B is a bottom view of the divided piece 21.
  • Each of the plurality of divided pieces 21 has a side surface 22, a side surface 23, a bottom surface 24, and a top surface 25, as shown in FIGS. 4A and 4B.
  • Each of the plurality of divided pieces further has a first convex portion 26 and a second convex portion 27.
  • the side surface 22 is a surface facing the side surface 11b (first surface 11ba to fourth surface 11bd) in a state where the cutting edge tip 20 is attached to the base material 10.
  • the side surface 22 has a shape along the side surface 11b (first surface 11ba to fourth surface 11bd).
  • the side surface 23 is the opposite surface of the side surface 22, and is a surface connected to the side surface 10c when the cutting edge tip 20 is attached to the base material 10.
  • the side surface 23 is a flank of the cutting insert 100.
  • the bottom surface 24 is a surface facing the top surface 10b when the cutting edge tip 20 is attached to the base material 10.
  • the upper surface 25 is the opposite surface of the bottom surface 24.
  • the upper surface 25 is flush with the upper surface 11a, for example, when the cutting edge tip 20 is attached to the base material 10.
  • the upper surface 25 is a rake face of the cutting insert 100.
  • the ridges of the side surface 23 and the upper surface 25 serve as the cutting edge of the cutting insert 100.
  • the first convex portion 26 is at one end of the split piece 21 in the longitudinal direction
  • the second convex portion 27 is at the other end of the split piece 21 in the longitudinal direction.
  • the first convex portion 26 projects from one end in the longitudinal direction of the split piece 21 along a direction intersecting the longitudinal direction of the split piece 21.
  • the second convex portion 27 projects from the other end in the longitudinal direction of the split piece 21 along the longitudinal direction of the split piece 21.
  • FIG. 5 is a plan view of the cutting insert 100. As shown in FIG. 5, the first convex portion 26 of the divided piece 21a sandwiches the second convex portion 27 of the divided piece 21c with the third surface 11bc. The first convex portion 26 of the divided piece 21b sandwiches the second convex portion 27 of the divided piece 21d with the fourth surface 11bd.
  • the first convex portion 26 of the split piece 21c sandwiches the second convex portion 27 of the split piece 21b between the second surface 11bb and the second surface 11bb.
  • the first convex portion 26 of the divided piece 21d sandwiches the second convex portion 27 of the divided piece 21a with the first surface 11ba. That is, in a state where the cutting edge tip 20 is attached to the base material 10, the first convex portion 26 of a certain divided piece 21 is the second of another divided piece 21 adjacent to the divided piece 21 between the side surface 11b.
  • the convex portion 27 is sandwiched.
  • the positions of the center of gravity of the divided pieces 21a to 21d are set to the center of gravity position P5 to the center of gravity position P8, respectively.
  • the center of gravity position P5 is located at a position shifted from the apex P1 to one end side of the split piece 21a in the longitudinal direction of the split piece 21a
  • the center of gravity position P6 is the position of the split piece 21b. It is located at a position shifted from the apex P2 to one end side of the split piece 21b in the longitudinal direction.
  • the center of gravity position P7 is located at a position shifted from the apex P3 to one end side of the split piece 21c in the longitudinal direction of the split piece 21c, and the center of gravity position P8 is the split piece. It is located at a position shifted from the apex P4 to one end side of the divided piece 21d in the longitudinal direction of 21d. That is, each of the positions of the center of gravity of the plurality of divided pieces 21 is deviated from the apex of the curve indicating the side surface 11b in the longitudinal direction of the divided pieces 21.
  • the cutting edge tip 20 is brazed to the base material 10. More specifically, the side surface 22 is joined to the side surface 11b, and the bottom surface 24 is joined to the top surface 10b. As a result, the cutting edge tip 20 is attached to the base material 10.
  • FIG. 6 is a process diagram showing a manufacturing method of the cutting insert 100.
  • the method for manufacturing the cutting insert 100 includes a preparation step S1 and a brazing step S2.
  • the preparation step S1 the base material 10 and the cutting edge tip 20 (plurality of divided pieces 21) are prepared.
  • the cutting edge tip 20 is brazed to the base material 10. More specifically, first, the brazing filler metal is applied on the upper surface 10b and the side surface 11b. Second, each of the plurality of divided pieces 21 is placed on the base material 10 so that the bottom surface 24 and the side surface 22 face the upper surface 10b and the side surface 11b, respectively, via the brazing material. Thirdly, the base material 10 on which the plurality of divided pieces 21 are placed is put into the heating furnace. As a result, the brazing material is melted, and the plurality of divided pieces 21 and the base material 10 are joined.
  • cutting insert 100A the cutting insert according to the first comparative example
  • cutting insert 100B the cutting insert according to the second comparative example
  • FIG. 7 is an exploded perspective view of the cutting insert 100A.
  • the cutting insert 100A has a base material 10 and a cutting edge tip 20.
  • the base material 10 does not have a protrusion 11.
  • the cutting edge tip 20 is not divided into a plurality of divided pieces 21, but is attached to the entire surface of the upper surface 10b by brazing. In these respects, the configuration of the cutting insert 100A is different from the configuration of the cutting insert 100.
  • the cutting edge tip 20 is not divided into a plurality of divided pieces 21, when the cutting edge tip 20 is brazed to the base material 10, the surface tension of the molten brazing material causes the plurality of divided pieces 21 to be brazed. No gap is formed between each.
  • the cutting edge tip 20 is attached over the entire surface of the upper surface 10b, the amount of the material used for the cutting edge tip 20 increases, and the manufacturing cost of the cutting insert increases. This is more remarkable when the cutting edge tip 20 is made of a relatively expensive material such as a cubic boron nitride sintered body or a polycrystalline diamond sintered body.
  • the cutting insert 100A in order to form the through hole 30, it is necessary to perform drilling not only on the base material 10 but also on the cutting edge tip 20. As a result of the increase in manufacturing time and processing cost for performing this drilling process, the mass productivity of the cutting insert 100A is low.
  • FIG. 8 is a perspective view of the cutting insert 100B.
  • the cutting insert 100B has a base material 10 and a cutting edge tip 20.
  • the base material 10 of the cutting insert 100B is the same as the base material 10 of the cutting insert 100.
  • the cutting edge tip 20 of the cutting insert 100B is similar to the cutting edge tip 20 of the cutting insert 100 in that it is divided into a plurality of divided pieces 21.
  • each of the plurality of divided pieces 21 does not have the first convex portion 26 and the second convex portion 27.
  • the configuration of the cutting insert 100B is different from the configuration of the cutting insert 100.
  • the cutting edge tip 20 is arranged so as to surround the protruding portion 11 in an annular shape, the base material 10 does not have the protruding portion 11, and the cutting edge tip 20 must be attached to the entire surface of the upper surface 10b.
  • the amount of material used for the cutting edge tip 20 is reduced as compared to the case where it must be.
  • the cutting insert 100B it is not necessary to drill a hole in the cutting edge tip 20 in order to form the through hole 30. Therefore, according to the cutting insert 100B, the manufacturing cost can be reduced as compared with the cutting insert 100A.
  • the cutting edge tip 20 is divided into a plurality of divided pieces 21, when the cutting edge tip 20 is brazed to the base material 10, the surface tension of the molten brazing material causes the plurality of divided pieces.
  • a gap may be formed between each of the 21.
  • FIG. 9 is a schematic diagram for explaining the effect of the cutting insert 100.
  • the first surface 11ba is convex toward the side opposite to the through hole 30, when the brazing filler metal is melted, the surface tension of the melted brazing filler metal is increased. As a result, the split piece 21a tries to rotate along the first surface 11ba.
  • the center of gravity position P5 is displaced from the apex P1 to one end side of the divided piece 21a in the longitudinal direction of the divided piece 21a, the rotation of the divided piece 21a due to the surface tension of the molten brazing material is caused by the first convex portion 26.
  • the second convex portion 27 tends to rotate away from the first surface 11ba (that is, it tends to rotate counterclockwise in FIG. 9).
  • the divided pieces 21b to 21d also tend to rotate in the same direction as the divided pieces 21a.
  • first convex portion 26 of the split piece 21a sandwiches the second convex portion 27 of the split piece 21c between the third surface 11bc and the first convex portion 26 of the split piece 21b with the fourth surface 11bd.
  • the second convex portion 27 of the divided piece 21d is sandwiched between them.
  • first convex portion 26 of the split piece 21c sandwiches the second convex portion 27 of the split piece 21b between the second surface 11bb and the first convex portion 26 of the split piece 21d with the first surface 11ba.
  • the second convex portion 27 of the divided piece 21a is sandwiched between them.
  • the rotation of the split piece 21c in which the second convex portion 27 tries to move away from the third surface 11bc is suppressed by the rotation of the split piece 21a in which the first convex portion 26 tries to approach the third surface 11bc, and the second convex portion 26.
  • the rotation of the split piece 21d in which the portion 27 tends to move away from the fourth surface 11bd is suppressed by the rotation of the split piece 21b in which the first convex portion 26 tries to approach the fourth surface 11bd.
  • the rotation of the split piece 21b in which the second convex portion 27 tries to move away from the second surface 11bb is suppressed by the rotation of the split piece 21c in which the first convex portion 26 tries to approach the second surface 11bb, and the second convex portion 26
  • the rotation of the split piece 21a in which the portion 27 tends to move away from the first surface 11ba is suppressed by the rotation of the split piece 21d in which the first convex portion 26 tries to approach the first surface 11ba.
  • the rotation of the plurality of divided pieces 21 is mutually suppressed by the same direction of rotation due to the surface tension of the molten brazing material of each of the plurality of divided pieces 21. , It is suppressed that a gap is generated between each of the plurality of divided pieces 21.
  • the cutting insert 100 similarly to the cutting insert 100B, the amount of the material used for the cutting edge tip 20 can be reduced, and the processing cost for forming the through hole 30 can be reduced. Further, in the cutting insert 100, since the ridgeline between the side surface 23 located on the first convex portion 26 and the upper surface 25 located on the first convex portion 26 can be used as a cutting edge, the cutting edge is compared with the cutting insert 100B. More portions of the insert 20 can be used as cutting edges.
  • the width of the split piece 21 can be narrowed, so that the amount of the material used for the cutting edge tip 20 can be further reduced.
  • 100, 100A, 100B cutting insert 10 base material, 10a bottom surface, 10b top surface, 10ba 1st side, 10bb 2nd side, 10bb 3rd side, 10bd 4th side, 10c side surface, 11 protrusion, 11a top surface, 11b side surface , 11ba 1st surface, 11bb 2nd surface, 11bc 3rd surface, 11bd 4th surface, 20 cutting edge tip, 21,21a, 21b, 21c, 21d split piece, 22, 23 side surface, 24 bottom surface, 25 top surface, 26th 1 convex part, 27 2nd convex part, 30 through hole, C center, DIS1, DIS2 distance, P1, P2, P3, P4 vertex, P5, P6, P7, P8 center of gravity position, S1 preparation process, S2 brazing process.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)

Abstract

This cutting insert comprises a base member and cutting tips. In the thickness direction of the base member, the base member has a bottom surface and a top surface that is the opposite surface to the bottom surface. In a plan view seen along the thickness direction, the top surface has a polygonal shape consisting of a plurality of sides. The top surface is provided with a protruding portion that protrudes toward the opposite side to the bottom surface in the thickness direction. In the protruding portion, a through hole that passes through the base member in the thickness direction is formed. The protruding portion has side surfaces that are joined to the top surface. In a plan view seen along the thickness direction, the side surfaces comprise curve lines that are convex to the side opposite to the through hole. The curve lines include a plurality of vertices at positions where the distance to the plurality of sides is smallest. The cutting tips are brazed to the top surface and the side surfaces so as to annularly surround the protruding portion.

Description

切削インサート及び切削インサートの製造方法Cutting inserts and manufacturing methods for cutting inserts
　本開示は、切削インサート及び切削インサートの製造方法に関する。 This disclosure relates to a cutting insert and a method for manufacturing the cutting insert.
　特許文献１（実開昭６０－５３４０４号公報）には、切削工具が記載されている。特許文献１に記載の切削工具は、台金と、複数の硬質焼結体片とを有している。複数の焼結体片は、台金に接合されている。 Patent Document 1 (Japanese Patent Publication No. 60-53404) describes a cutting tool. The cutting tool described in Patent Document 1 has a base metal and a plurality of hard sintered body pieces. A plurality of sintered body pieces are joined to a base metal.
実開昭６０－５３４０４号公報Jitsukaisho 60-53404 Gazette
　本開示の切削インサートは、基材と、刃先チップとを備える。基材は、基材の厚さ方向において、底面と、底面の反対面である上面とを有している。上面は、厚さ方向に沿って見た平面視において、複数の辺により構成される多角形形状を有している。上面には、厚さ方向に沿って底面とは反対側に突出する突出部が設けられている。突出部には、基材を厚さ方向に沿って貫通している貫通穴が形成されている。突出部は、上面に連なっている側面を有している。側面は、厚さ方向に沿って見た平面視において、貫通穴とは反対側に向かって凸の曲線により構成されている。曲線は、複数の辺の各々との距離が最小となる位置において、複数の頂点を含む。刃先チップは、突出部を環状に取り囲むように上面及び側面にろう付けされている。刃先チップは、複数の分割片により構成されている。複数の分割片の数は、複数の辺の数に等しい。複数の分割片の長手方向の各々は、それぞれ、複数の辺の各々に沿っている。複数の分割片の各々は、長手方向において、第１端と、第１端の反対側における端である第２端とを有している。複数の分割片の各々は、第１端において第１凸部を有するとともに、第２端において第２凸部を有している。複数の分割片のうちの１つの分割片の第１凸部は、複数の分割片のうちの１つの分割片と隣り合う別の分割片の第２凸部を側面との間に挟み込んでいる。複数の分割片の重心位置の各々は、それぞれ、長手方向において、複数の頂点の各々とずれた位置にある。 The cutting insert of the present disclosure includes a base material and a cutting edge tip. The base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material. The upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction. The upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction. A through hole is formed in the protrusion so as to penetrate the base material along the thickness direction. The protrusion has a side surface that is continuous with the upper surface. The side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction. The curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum. The cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape. The cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides. Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides. Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end. Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end. The first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. .. Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
図１は、切削インサート１００の斜視図である。FIG. 1 is a perspective view of the cutting insert 100. 図２は、基材１０の斜視図である。FIG. 2 is a perspective view of the base material 10. 図３は、基材１０の平面図である。FIG. 3 is a plan view of the base material 10. 図４Ａは、分割片２１の平面図である。FIG. 4A is a plan view of the divided piece 21. 図４Ｂは、分割片２１の底面図である。FIG. 4B is a bottom view of the divided piece 21. 図５は、切削インサート１００の平面図である。FIG. 5 is a plan view of the cutting insert 100. 図６は、切削インサート１００の製造方法を示す工程図である。FIG. 6 is a process diagram showing a method of manufacturing the cutting insert 100. 図７は、切削インサート１００Ａの分解斜視図である。FIG. 7 is an exploded perspective view of the cutting insert 100A. 図８は、切削インサート１００Ｂの斜視図である。FIG. 8 is a perspective view of the cutting insert 100B. 図９は、切削インサート１００の効果を説明するための模式図である。FIG. 9 is a schematic diagram for explaining the effect of the cutting insert 100.
　［本開示が解決しようとする課題］
　特許文献１に記載の切削工具においては、台金に複数の硬質焼結体片をろう付け使用とする際に、ろう材の表面張力により、複数の硬質焼結体片の各々の位置がずれてしまうことがある。その結果、複数の硬質焼結体片の各々の間に、隙間が生じることがある。 [Problems to be solved by this disclosure]
In the cutting tool described in Patent Document 1, when a plurality of hard sintered body pieces are brazed to a base metal, the positions of the plurality of hard sintered body pieces are displaced due to the surface tension of the brazing material. It may end up. As a result, a gap may occur between each of the plurality of hard sintered pieces.
　本開示は、上記のような従来技術の問題点に鑑みてなされたものである。より具体的には、本開示は、刃先チップを構成している複数の分割片の各々の間に隙間が生じることを抑制可能な切削インサート及び切削インサートの製造方法を提供するものである。 This disclosure has been made in view of the problems of the prior art as described above. More specifically, the present disclosure provides a cutting insert and a method for manufacturing a cutting insert, which can suppress the formation of a gap between each of a plurality of divided pieces constituting the cutting edge tip.
　［本開示の効果］
　本開示の切削インサートによると、刃先チップを構成している複数の分割片の各々の間に隙間が生じることを抑制できる。 [Effect of this disclosure]
According to the cutting insert of the present disclosure, it is possible to suppress the formation of a gap between each of the plurality of divided pieces constituting the cutting edge tip.
　［本開示の実施形態の説明］
　まず、本開示の実施形態を、列挙して説明する。 [Explanation of Embodiments of the present disclosure]
First, the embodiments of the present disclosure will be listed and described.
　（１）実施形態に係る切削インサートは、基材と、刃先チップとを備える。基材は、基材の厚さ方向において、底面と、底面の反対面である上面とを有している。上面は、厚さ方向に沿って見た平面視において、複数の辺により構成される多角形形状を有している。上面には、厚さ方向に沿って底面とは反対側に突出する突出部が設けられている。突出部には、基材を厚さ方向に沿って貫通している貫通穴が形成されている。突出部は、上面に連なっている側面を有している。側面は、厚さ方向に沿って見た平面視において、貫通穴とは反対側に向かって凸の曲線により構成されている。曲線は、複数の辺の各々との距離が最小となる位置において、複数の頂点を含んでいる。刃先チップは、突出部を環状に取り囲むように上面及び側面にろう付けされている。刃先チップは、複数の分割片により構成されている。複数の分割片の数は、複数の辺の数に等しい。複数の分割片の長手方向の各々は、それぞれ、複数の辺の各々に沿っている。複数の分割片の各々は、長手方向において、第１端と、第１端の反対側における端である第２端とを有している。複数の分割片の各々は、第１端において第１凸部を有するとともに、第２端において第２凸部を有している。複数の分割片のうちの１つの分割片の第１凸部は、複数の分割片のうちの１つの分割片と隣り合う別の分割片の第２凸部を側面との間に挟み込んでいる。複数の分割片の重心位置の各々は、それぞれ、長手方向において、複数の頂点の各々とずれた位置にある。 (1) The cutting insert according to the embodiment includes a base material and a cutting edge tip. The base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material. The upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction. The upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction. A through hole is formed in the protrusion so as to penetrate the base material along the thickness direction. The protrusion has a side surface that is continuous with the upper surface. The side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction. The curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum. The cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape. The cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides. Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides. Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end. Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end. The first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. .. Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
　上記（１）の切削インサートによると、刃先チップを構成している複数の分割片の各々の間に隙間が生じることを抑制できる。また、上記（１）の切削インサートによると、刃先チップに使用される素材の量及び刃先チップに対する加工の費用を低減することができる。さらに、上記（１）の切削インサートによると、刃先チップのより多くの部分を切れ刃として利用することができる。 According to the cutting insert of (1) above, it is possible to suppress the formation of a gap between each of the plurality of divided pieces constituting the cutting edge tip. Further, according to the cutting insert of the above (1), the amount of the material used for the cutting edge tip and the processing cost for the cutting edge tip can be reduced. Further, according to the cutting insert of (1) above, a larger portion of the cutting edge tip can be used as a cutting edge.
　（２）上記（１）の切削インサートにおいて、曲線は、複数の部分円弧により構成されていてもよい。複数の部分円弧の各々は、それぞれ、複数の辺の各々に対向していてもよい。厚さ方向に沿って見た平面視において、突出部の角と貫通穴の中心との間の距離は、複数の頂点の各々と中心との間の距離よりも大きくてもよい。この場合、刃先チップに使用される素材の量をさらに低減することができる。 (2) In the cutting insert of (1) above, the curve may be composed of a plurality of partial arcs. Each of the plurality of partial arcs may face each of the plurality of sides. In a plan view along the thickness direction, the distance between the corner of the protrusion and the center of the through hole may be greater than the distance between each of the plurality of vertices and the center. In this case, the amount of material used for the cutting edge tip can be further reduced.
　（３）上記（１）又は（２）の切削インサートにおいて、刃先チップは、立方晶窒化硼素焼結体又は多結晶ダイヤモンド焼結体により形成されていてもよい。 (3) In the cutting insert of (1) or (2) above, the cutting edge tip may be formed of a cubic boron nitride sintered body or a polycrystalline diamond sintered body.
　（４）実施形態に係る切削インサートの製造方法は、基材及び刃先チップを準備する工程と、刃先チップを基材にろう付けする工程とを備える。基材は、基材の厚さ方向において、底面と、底面の反対面である上面とを有している。上面は、厚さ方向に沿って見た平面視において、複数の辺により構成される多角形形状を有している。上面には、厚さ方向に沿って底面とは反対側に突出する突出部が設けられている。突出部には、厚さ方向に沿って基材を貫通している貫通穴が形成されている。突出部は、上面に連なっている側面を有している。側面は、厚さ方向に沿って見た平面視において、貫通穴とは反対側に向かって凸の曲線により構成されている。曲線は、複数の辺の各々との距離が最小となる位置において、複数の頂点を含んでいる。刃先チップは、突出部を環状に取り囲むように上面及び側面にろう付けされている。刃先チップは、複数の分割片により構成されている。複数の分割片の数は、複数の辺の数に等しい。複数の分割片の長手方向の各々は、それぞれ、複数の辺の各々に沿っている。複数の分割片の各々は、長手方向において、第１端と、第１端の反対側における端である第２端とを有している。複数の分割片の各々は、第１端において第１凸部を有するとともに、第２端において第２凸部を有している。複数の分割片のうちの１つの分割片の第１凸部は、複数の分割片のうちの１つの分割片と隣り合う別の分割片の第２凸部を側面との間に挟み込んでいる。複数の分割片の重心位置の各々は、それぞれ、長手方向において、複数の頂点の各々とずれた位置にある。 (4) The method for manufacturing a cutting insert according to an embodiment includes a step of preparing a base material and a cutting edge tip, and a step of brazing the cutting edge tip to the base material. The base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material. The upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction. The upper surface is provided with a protrusion that protrudes from the bottom surface in the thickness direction. A through hole is formed in the protrusion so as to penetrate the base material along the thickness direction. The protrusion has a side surface that is continuous with the upper surface. The side surface is composed of a curved line that is convex toward the side opposite to the through hole in a plan view along the thickness direction. The curve contains a plurality of vertices at the position where the distance from each of the plurality of sides is the minimum. The cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape. The cutting edge tip is composed of a plurality of divided pieces. The number of pieces is equal to the number of sides. Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides. Each of the plurality of pieces has a first end in the longitudinal direction and a second end which is an end opposite to the first end. Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end. The first convex portion of one of the plurality of divided pieces sandwiches the second convex portion of another divided piece adjacent to one of the plurality of divided pieces between the side surface and the side surface. .. Each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
　上記（４）の切削インサートの製造方法によると、刃先チップを構成している複数の分割片の各々の間に隙間が生じることを抑制できる。また、上記（４）の切削インサートの製造方法によると、刃先チップに必要な素材の使用量及び刃先チップに対する加工の費用を低減することができる。さらに、上記（４）の切削インサートの製造方法によると、刃先チップのより多くの部分を切れ刃として利用することができる。 According to the method for manufacturing a cutting insert according to (4) above, it is possible to suppress the formation of a gap between each of a plurality of divided pieces constituting the cutting edge tip. Further, according to the method for manufacturing a cutting insert according to the above (4), it is possible to reduce the amount of material used for the cutting edge tip and the processing cost for the cutting edge tip. Further, according to the method for manufacturing a cutting insert according to the above (4), a larger portion of the cutting edge tip can be used as a cutting edge.
　［本開示の実施形態の詳細］
　次に、本開示の実施形態の詳細を、図面を参照しながら説明する。以下の図面においては、同一又は相当する部分に同一の参照符号を付し、重複する説明は繰り返さないものとする。 [Details of Embodiments of the present disclosure]
Next, the details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts shall be designated by the same reference numerals, and duplicate explanations shall not be repeated.
　（実施形態に係る切削インサートの構成）
　以下に、実施形態に係る切削インサート（以下「切削インサート１００」とする）の構成を説明する。 (Structure of cutting insert according to embodiment)
Hereinafter, the configuration of the cutting insert (hereinafter referred to as “cutting insert 100”) according to the embodiment will be described.
　図１は、切削インサート１００の斜視図である。図１に示されるように、切削インサート１００は、基材１０と、刃先チップ２０とを有している。 FIG. 1 is a perspective view of the cutting insert 100. As shown in FIG. 1, the cutting insert 100 has a base material 10 and a cutting edge tip 20.
　＜基材１０＞
　基材１０は、例えば、超硬合金により形成されている。但し、基材１０は、超硬合金以外の材料により形成されていてもよい。図２は、基材１０の斜視図である。図３は、基材１０の平面図である。図２及び図３に示されるように、基材１０は、基材１０の厚さ方向において、底面１０ａと、上面１０ｂとを有している。上面１０ｂは、底面１０ａの反対面である。基材１０は、側面１０ｃをさらに有している。側面１０ｃは、底面１０ａ及び上面１０ｂに連なっている。 <Base material 10>
The base material 10 is formed of, for example, a cemented carbide. However, the base material 10 may be formed of a material other than the cemented carbide. FIG. 2 is a perspective view of the base material 10. FIG. 3 is a plan view of the base material 10. As shown in FIGS. 2 and 3, the base material 10 has a bottom surface 10a and a top surface 10b in the thickness direction of the base material 10. The upper surface 10b is the opposite surface of the bottom surface 10a. The base material 10 further has a side surface 10c. The side surface 10c is connected to the bottom surface 10a and the top surface 10b.
　上面１０ｂは、基材１０の厚さ方向に沿って見た平面視（以下においては、単に「平面視」とする）において、多角形形状を有している。この多角形形状は、数学的に厳密な多角形形状でなくてもよい。例えば、上面１０ｂの角が丸まっている場合でも、基材１０が平面視において多角形形状を有していることになる。図３の例では、上面１０ｂは、四角形形状（正方形形状）を有している。 The upper surface 10b has a polygonal shape in a plan view (hereinafter, simply referred to as "plan view") viewed along the thickness direction of the base material 10. This polygon shape does not have to be a mathematically exact polygon shape. For example, even when the corners of the upper surface 10b are rounded, the base material 10 has a polygonal shape in a plan view. In the example of FIG. 3, the upper surface 10b has a quadrangular shape (square shape).
　上記の多角形形状（上面１０ｂ）は、第１辺１０ｂａと、第２辺１０ｂｂと、第３辺１０ｂｃと、第４辺１０ｂｄとにより構成されている。第１辺１０ｂａは、一方端において第３辺１０ｂｃに連なっており、他方端において第４辺１０ｂｄに連なっている。第２辺１０ｂｂは、一方端において第４辺１０ｂｄに連なっており、他方端において第３辺１０ｂｃに連なっている。 The above polygonal shape (upper surface 10b) is composed of a first side 10ba, a second side 10bb, a third side 10bc, and a fourth side 10bd. The first side 10ba is connected to the third side 10bc at one end, and is connected to the fourth side 10b at the other end. The second side 10bb is connected to the fourth side 10bd at one end, and is connected to the third side 10bb at the other end.
　上面１０ｂには、突出部１１が設けられている。突出部１１は、基材１０の厚さ方向に沿って底面１０ａとは反対側に向かって突出している。すなわち、突出部１１と上面１０ｂとの間には、段差がある。突出部１１は、平面視において、上面１０ｂの中央に位置している。 A protrusion 11 is provided on the upper surface 10b. The protruding portion 11 projects toward the side opposite to the bottom surface 10a along the thickness direction of the base material 10. That is, there is a step between the protrusion 11 and the upper surface 10b. The protrusion 11 is located at the center of the upper surface 10b in a plan view.
　突出部１１は、上面１１ａと、側面１１ｂとを有している。上面１１ａは、例えば、上面１０ｂ（底面１０ａ）に平行になっている。側面１１ｂは、上面１１ａ及び上面１０ｂに連なっている。 The protruding portion 11 has an upper surface 11a and a side surface 11b. The upper surface 11a is parallel to, for example, the upper surface 10b (bottom surface 10a). The side surface 11b is connected to the upper surface 11a and the upper surface 10b.
　突出部１１（上面１１ａ）には、貫通穴３０が形成されている。貫通穴３０は、基材１０の厚さ方向に沿って、基材１０（切削インサート１００）を貫通している。貫通穴３０は、平面視において、突出部１１の中央（上面１１ａの中央）に位置している。貫通穴３０は、平面視において、円形を有している。平面視における貫通穴３０の中心を、中心Ｃとする。 A through hole 30 is formed in the protruding portion 11 (upper surface 11a). The through hole 30 penetrates the base material 10 (cutting insert 100) along the thickness direction of the base material 10. The through hole 30 is located at the center of the protrusion 11 (center of the upper surface 11a) in a plan view. The through hole 30 has a circular shape in a plan view. The center of the through hole 30 in a plan view is defined as the center C.
　図示されていないが、貫通穴３０にクランプねじが通される。このクランプねじがホルダに螺合されることにより、切削インサート１００は、ホルダ（図示せず）に締結されて固定される。 Although not shown, the clamp screw is passed through the through hole 30. By screwing this clamp screw into the holder, the cutting insert 100 is fastened and fixed to the holder (not shown).
　平面視において、側面１１ｂは、貫通穴３０とは反対側に向かって凸の曲線により構成されている。より具体的には、側面１１ｂは、第１面１１ｂａと、第２面１１ｂｂと、第３面１１ｂｃと、第４面１１ｂｄとにより構成されている。第１面１１ｂａ～第４面１１ｂｄは、それぞれ、第１辺１０ｂａ～第４辺１０ｂｄに対向している。 In a plan view, the side surface 11b is composed of a curved line that is convex toward the side opposite to the through hole 30. More specifically, the side surface 11b is composed of a first surface 11ba, a second surface 11bb, a third surface 11bc, and a fourth surface 11bd. The first surface 11ba to the fourth surface 11bd face the first side 10ba to the fourth side 10b, respectively.
　上面１０ｂに直交する平面視において、第１面１１ｂａ～第４面１１ｂｄは、部分円弧により構成されている。すなわち、側面１１ｂは、平面視において、上面１０ｂを構成している辺の数に等しい数の部分円弧により構成されている。これらの部分円弧の曲率半径は、平面視において貫通穴３０を示す円の半径よりも大きい。 In a plan view orthogonal to the upper surface 10b, the first surface 11ba to the fourth surface 11bd are composed of partial arcs. That is, the side surface 11b is composed of a number of partial arcs equal to the number of sides constituting the upper surface 10b in a plan view. The radius of curvature of these partial arcs is larger than the radius of the circle indicating the through hole 30 in a plan view.
　平面視において側面１１ｂを示す曲線は、上面１０ｂを構成している各辺との距離が最小となる位置に複数の頂点を有している。これらの頂点のうち、第１面１１ｂａを示す部分円弧の頂点を頂点Ｐ１とし、第２面１１ｂｂを示す部分円弧の頂点を頂点Ｐ２とし、第３面１１ｂｃを示す部分円弧の頂点を頂点Ｐ３とし、第４面１１ｂｄを示す部分円弧の頂点を頂点Ｐ４とする。 The curve showing the side surface 11b in a plan view has a plurality of vertices at positions where the distance from each side constituting the upper surface 10b is minimized. Of these vertices, the vertex of the partial arc indicating the first surface 11ba is the vertex P1, the vertex of the partial arc indicating the second surface 11bb is the vertex P2, and the vertex of the partial arc indicating the third surface 11bc is the vertex P3. , The apex of the partial arc indicating the fourth surface 11db is defined as the apex P4.
　平面視における突出部１１の角と中心Ｃとの間の距離を、距離ＤＩＳ１とする。平面視における頂点Ｐ１（頂点Ｐ２、頂点Ｐ３、頂点Ｐ４）と中心Ｃとの間の距離を、距離ＤＩＳ２とする。距離ＤＩＳ１は、例えば、距離ＤＩＳ２よりも大きい。 The distance between the corner of the protrusion 11 and the center C in a plan view is defined as the distance DIS1. The distance between the apex P1 (vertex P2, apex P3, apex P4) and the center C in the plan view is defined as the distance DIS2. The distance DIS1 is larger than, for example, the distance DIS2.
　＜刃先チップ２０＞
　刃先チップ２０は、例えば、立方晶窒化硼素焼結体により形成されている。立方晶窒化硼素粒子焼結体は、立方晶窒化硼素粒子とコバルト等のバインダとを含む焼結体である。刃先チップ２０は、多結晶ダイヤモンド焼結体により形成されていてもよい。多結晶ダイヤモンド焼結体は、ダイヤモンド粒子とコバルト等のバインダとを含む焼結体である。刃先チップ２０は、立方晶窒化硼素焼結体及び多結晶ダイヤモンド焼結体以外の基材１０よりも硬度の高い材料により形成されていてもよい。 <Blade tip 20>
The cutting edge tip 20 is formed of, for example, a cubic boron nitride sintered body. The cubic boron nitride particle sintered body is a sintered body containing cubic boron nitride particles and a binder such as cobalt. The cutting edge tip 20 may be formed of a polycrystalline diamond sintered body. The polycrystalline diamond sintered body is a sintered body containing diamond particles and a binder such as cobalt. The cutting edge tip 20 may be formed of a material having a hardness higher than that of the base material 10 other than the cubic boron nitride sintered body and the polycrystalline diamond sintered body.
　刃先チップ２０は、平面視において、複数の分割片２１に分割されている。複数の分割片２１の数は、４つである。すなわち、刃先チップ２０は、上面１０ｂを構成している辺の数に等しい数の分割片２１に分割されている。複数の分割片２１の各々は、例えば、同一形状になっている。以下において、これら４つの分割片を、それぞれ、分割片２１ａ、分割片２１ｂ、分割片２１ｃ及び分割片２１ｄとすることがある。 The cutting edge tip 20 is divided into a plurality of divided pieces 21 in a plan view. The number of the plurality of divided pieces 21 is four. That is, the cutting edge tip 20 is divided into a number of divided pieces 21 equal to the number of sides constituting the upper surface 10b. Each of the plurality of divided pieces 21 has, for example, the same shape. In the following, these four divided pieces may be referred to as a divided piece 21a, a divided piece 21b, a divided piece 21c, and a divided piece 21d, respectively.
　図１に示されるように、刃先チップ２０は、突出部１１の周囲を環状に取り囲むように上面１０ｂ上に配置されている。より具体的には、刃先チップ２０は、分割片２１ａの長手方向が第１辺１０ｂａに沿い、分割片２１ｂの長手方向が第２辺１０ｂｂに沿い、分割片２１ｃの長手方向が第３辺１０ｂｃに沿い、かつ分割片２１ｄの長手方向が第４辺１０ｂｄに沿うように、上面１０ｂ上に配置されている（図５参照）。 As shown in FIG. 1, the cutting edge tip 20 is arranged on the upper surface 10b so as to surround the periphery of the protrusion 11 in an annular shape. More specifically, in the cutting edge tip 20, the longitudinal direction of the split piece 21a is along the first side 10ba, the longitudinal direction of the split piece 21b is along the second side 10bb, and the longitudinal direction of the split piece 21c is the third side 10bc. The divided pieces 21d are arranged on the upper surface 10b so as to be along the fourth side 10bd (see FIG. 5).
　図４Ａは、分割片２１の平面図である。図４Ｂは、分割片２１の底面図である。複数の分割片２１の各々は、図４Ａ及び図４Ｂに示されるように、側面２２と、側面２３と、底面２４と、上面２５とを有している。複数の分割片の各々は、さらに、第１凸部２６と、第２凸部２７とを有している。 FIG. 4A is a plan view of the divided piece 21. FIG. 4B is a bottom view of the divided piece 21. Each of the plurality of divided pieces 21 has a side surface 22, a side surface 23, a bottom surface 24, and a top surface 25, as shown in FIGS. 4A and 4B. Each of the plurality of divided pieces further has a first convex portion 26 and a second convex portion 27.
　側面２２は、刃先チップ２０が基材１０に取り付けられた状態において側面１１ｂ（第１面１１ｂａ～第４面１１ｂｄ）に対向する面である。側面２２は、側面１１ｂ（第１面１１ｂａ～第４面１１ｂｄ）に沿った形状を有している。側面２３は、側面２２の反対面であり、刃先チップ２０が基材１０に取り付けられた状態において側面１０ｃに連なる面である。側面２３は、切削インサート１００の逃げ面となる。 The side surface 22 is a surface facing the side surface 11b (first surface 11ba to fourth surface 11bd) in a state where the cutting edge tip 20 is attached to the base material 10. The side surface 22 has a shape along the side surface 11b (first surface 11ba to fourth surface 11bd). The side surface 23 is the opposite surface of the side surface 22, and is a surface connected to the side surface 10c when the cutting edge tip 20 is attached to the base material 10. The side surface 23 is a flank of the cutting insert 100.
　底面２４は、刃先チップ２０が基材１０に取り付けられた状態において上面１０ｂに対向する面である。上面２５は、底面２４の反対面である。上面２５は、例えば、刃先チップ２０が基材１０に取り付けられた状態において上面１１ａと面一になっている。上面２５は、切削インサート１００のすくい面となる。側面２３と上面２５の稜線は、切削インサート１００の切れ刃となる。 The bottom surface 24 is a surface facing the top surface 10b when the cutting edge tip 20 is attached to the base material 10. The upper surface 25 is the opposite surface of the bottom surface 24. The upper surface 25 is flush with the upper surface 11a, for example, when the cutting edge tip 20 is attached to the base material 10. The upper surface 25 is a rake face of the cutting insert 100. The ridges of the side surface 23 and the upper surface 25 serve as the cutting edge of the cutting insert 100.
　第１凸部２６は分割片２１の長手方向における一方端にあり、第２凸部２７は分割片２１の長手方向における他方端にある。第１凸部２６は、分割片２１の長手方向における一方端から分割片２１の長手方向に交差する方向に沿って突出している。第２凸部２７は、分割片２１の長手方向における他方端から分割片２１の長手方向に沿って突出している。 The first convex portion 26 is at one end of the split piece 21 in the longitudinal direction, and the second convex portion 27 is at the other end of the split piece 21 in the longitudinal direction. The first convex portion 26 projects from one end in the longitudinal direction of the split piece 21 along a direction intersecting the longitudinal direction of the split piece 21. The second convex portion 27 projects from the other end in the longitudinal direction of the split piece 21 along the longitudinal direction of the split piece 21.
　図５は、切削インサート１００の平面図である。図５に示されるように、分割片２１ａの第１凸部２６は、第３面１１ｂｃとの間で、分割片２１ｃの第２凸部２７を挟み込んでいる。分割片２１ｂの第１凸部２６は、第４面１１ｂｄとの間で、分割片２１ｄの第２凸部２７を挟み込んでいる。 FIG. 5 is a plan view of the cutting insert 100. As shown in FIG. 5, the first convex portion 26 of the divided piece 21a sandwiches the second convex portion 27 of the divided piece 21c with the third surface 11bc. The first convex portion 26 of the divided piece 21b sandwiches the second convex portion 27 of the divided piece 21d with the fourth surface 11bd.
　分割片２１ｃの第１凸部２６は、第２面１１ｂｂとの間で、分割片２１ｂの第２凸部２７を挟み込んでいる。分割片２１ｄの第１凸部２６は、第１面１１ｂａとの間で、分割片２１ａの第２凸部２７を挟み込んでいる。すなわち、刃先チップ２０が基材１０に取り付けられた状態において、ある分割片２１の第１凸部２６は、側面１１ｂとの間に、当該分割片２１と隣り合う別の分割片２１の第２凸部２７を挟み込んでいる。 The first convex portion 26 of the split piece 21c sandwiches the second convex portion 27 of the split piece 21b between the second surface 11bb and the second surface 11bb. The first convex portion 26 of the divided piece 21d sandwiches the second convex portion 27 of the divided piece 21a with the first surface 11ba. That is, in a state where the cutting edge tip 20 is attached to the base material 10, the first convex portion 26 of a certain divided piece 21 is the second of another divided piece 21 adjacent to the divided piece 21 between the side surface 11b. The convex portion 27 is sandwiched.
　分割片２１ａ～分割片２１ｄの重心位置を、それぞれ、重心位置Ｐ５～重心位置Ｐ８とする。刃先チップ２０が基材１０に取り付けられた状態において、重心位置Ｐ５は分割片２１ａの長手方向において頂点Ｐ１から分割片２１ａの一方端側にずれた位置にあり、重心位置Ｐ６は分割片２１ｂの長手方向において頂点Ｐ２から分割片２１ｂの一方端側にずれた位置にある。 The positions of the center of gravity of the divided pieces 21a to 21d are set to the center of gravity position P5 to the center of gravity position P8, respectively. In the state where the cutting edge tip 20 is attached to the base material 10, the center of gravity position P5 is located at a position shifted from the apex P1 to one end side of the split piece 21a in the longitudinal direction of the split piece 21a, and the center of gravity position P6 is the position of the split piece 21b. It is located at a position shifted from the apex P2 to one end side of the split piece 21b in the longitudinal direction.
　また、刃先チップ２０が基材１０に取り付けられた状態において、重心位置Ｐ７は分割片２１ｃの長手方向において頂点Ｐ３から分割片２１ｃの一方端側にずれた位置にあり、重心位置Ｐ８は分割片２１ｄの長手方向において頂点Ｐ４から分割片２１ｄの一方端側にずれた位置にある。すなわち、複数の分割片２１の重心位置の各々は、それぞれ、分割片２１の長手方向において、側面１１ｂを示す曲線の頂点からずれている。 Further, in the state where the cutting edge tip 20 is attached to the base material 10, the center of gravity position P7 is located at a position shifted from the apex P3 to one end side of the split piece 21c in the longitudinal direction of the split piece 21c, and the center of gravity position P8 is the split piece. It is located at a position shifted from the apex P4 to one end side of the divided piece 21d in the longitudinal direction of 21d. That is, each of the positions of the center of gravity of the plurality of divided pieces 21 is deviated from the apex of the curve indicating the side surface 11b in the longitudinal direction of the divided pieces 21.
　刃先チップ２０は、基材１０にろう付けされている。より具体的には、側面２２が側面１１ｂに接合されており、底面２４が上面１０ｂに接合されている。これにより、刃先チップ２０が、基材１０に取り付けられている。 The cutting edge tip 20 is brazed to the base material 10. More specifically, the side surface 22 is joined to the side surface 11b, and the bottom surface 24 is joined to the top surface 10b. As a result, the cutting edge tip 20 is attached to the base material 10.
　（実施形態に係る切削インサートの製造方法）
　以下に、切削インサート１００の製造方法を説明する。 (Manufacturing method of cutting insert according to the embodiment)
The manufacturing method of the cutting insert 100 will be described below.
　図６は、切削インサート１００の製造方法を示す工程図である。切削インサート１００の製造方法は、図６に示されるように、準備工程Ｓ１と、ろう付け工程Ｓ２とを有している。準備工程Ｓ１においては、基材１０及び刃先チップ２０（複数の分割片２１）が準備される。 FIG. 6 is a process diagram showing a manufacturing method of the cutting insert 100. As shown in FIG. 6, the method for manufacturing the cutting insert 100 includes a preparation step S1 and a brazing step S2. In the preparation step S1, the base material 10 and the cutting edge tip 20 (plurality of divided pieces 21) are prepared.
　ろう付け工程Ｓ２においては、刃先チップ２０の基材１０へのろう付けが行われる。より具体的には、第１に、上面１０ｂ及び側面１１ｂ上に、ろう材が塗布される。第２に、複数の分割片２１の各々が、ろう材を介して底面２４及び側面２２がそれぞれ上面１０ｂ及び側面１１ｂに対向するように基材１０上に載置される。第３に、複数の分割片２１が載置された基材１０が、加熱炉内に投入される。これにより、ろう材が溶融し、複数の分割片２１と基材１０との接合が行われる。 In the brazing step S2, the cutting edge tip 20 is brazed to the base material 10. More specifically, first, the brazing filler metal is applied on the upper surface 10b and the side surface 11b. Second, each of the plurality of divided pieces 21 is placed on the base material 10 so that the bottom surface 24 and the side surface 22 face the upper surface 10b and the side surface 11b, respectively, via the brazing material. Thirdly, the base material 10 on which the plurality of divided pieces 21 are placed is put into the heating furnace. As a result, the brazing material is melted, and the plurality of divided pieces 21 and the base material 10 are joined.
　（実施形態に係る切削インサートの効果）
　以下に、切削インサート１００の効果を、第１比較例に係る切削インサート（以下「切削インサート１００Ａ」とする）及び第２比較例に係る切削インサート（以下「切削インサート１００Ｂ」とする）と対比しながら説明する。 (Effect of cutting insert according to the embodiment)
Below, the effect of the cutting insert 100 is compared with the cutting insert according to the first comparative example (hereinafter referred to as “cutting insert 100A”) and the cutting insert according to the second comparative example (hereinafter referred to as “cutting insert 100B”). I will explain while.
　図７は、切削インサート１００Ａの分解斜視図である。図７に示されるように、切削インサート１００Ａは、基材１０と、刃先チップ２０とを有している。切削インサート１００Ａにおいて、基材１０は、突出部１１を有していない。また、切削インサート１００Ａにおいて、刃先チップ２０は、複数の分割片２１に分割されておらず、上面１０ｂの全面にろう付けにより取り付けられている。これらの点に関して、切削インサート１００Ａの構成は、切削インサート１００の構成と異なっている。 FIG. 7 is an exploded perspective view of the cutting insert 100A. As shown in FIG. 7, the cutting insert 100A has a base material 10 and a cutting edge tip 20. In the cutting insert 100A, the base material 10 does not have a protrusion 11. Further, in the cutting insert 100A, the cutting edge tip 20 is not divided into a plurality of divided pieces 21, but is attached to the entire surface of the upper surface 10b by brazing. In these respects, the configuration of the cutting insert 100A is different from the configuration of the cutting insert 100.
　切削インサート１００Ａにおいては、刃先チップ２０が複数の分割片２１に分割されていないため、刃先チップ２０を基材１０にろう付けする際に、溶融したろう材の表面張力により複数の分割片２１の各々の間に隙間が形成されることはない。 In the cutting insert 100A, since the cutting edge tip 20 is not divided into a plurality of divided pieces 21, when the cutting edge tip 20 is brazed to the base material 10, the surface tension of the molten brazing material causes the plurality of divided pieces 21 to be brazed. No gap is formed between each.
　しかしながら、切削インサート１００Ａにおいては、上面１０ｂの全面にわたって刃先チップ２０が取り付けられるため、刃先チップ２０に使用される素材の量が増加し、切削インサートの製造コストが増大する。このことは、刃先チップ２０が立方晶窒化硼素焼結体や多結晶ダイヤモンド焼結体のように相対的にコストの高い素材が用いられる場合により顕著である。 However, in the cutting insert 100A, since the cutting edge tip 20 is attached over the entire surface of the upper surface 10b, the amount of the material used for the cutting edge tip 20 increases, and the manufacturing cost of the cutting insert increases. This is more remarkable when the cutting edge tip 20 is made of a relatively expensive material such as a cubic boron nitride sintered body or a polycrystalline diamond sintered body.
　また、切削インサート１００Ａにおいては、貫通穴３０を形成するために、基材１０に対してのみならず、刃先チップ２０に対する穴開け加工を行う必要がある。この穴開け加工を行うために製造に要する時間及び加工費用が増大する結果、切削インサート１００Ａの量産性は低い。 Further, in the cutting insert 100A, in order to form the through hole 30, it is necessary to perform drilling not only on the base material 10 but also on the cutting edge tip 20. As a result of the increase in manufacturing time and processing cost for performing this drilling process, the mass productivity of the cutting insert 100A is low.
　図８は、切削インサート１００Ｂの斜視図である。図８に示されるように、切削インサート１００Ｂは、基材１０と、刃先チップ２０とを有している。切削インサート１００Ｂの基材１０は、切削インサート１００の基材１０と同様である。切削インサート１００Ｂの刃先チップ２０は、複数の分割片２１に分割されている点において、切削インサート１００の刃先チップ２０と同様である。 FIG. 8 is a perspective view of the cutting insert 100B. As shown in FIG. 8, the cutting insert 100B has a base material 10 and a cutting edge tip 20. The base material 10 of the cutting insert 100B is the same as the base material 10 of the cutting insert 100. The cutting edge tip 20 of the cutting insert 100B is similar to the cutting edge tip 20 of the cutting insert 100 in that it is divided into a plurality of divided pieces 21.
　しかしながら、切削インサート１００Ｂにおいて、複数の分割片２１の各々は、第１凸部２６及び第２凸部２７を有していない。この点に関して、切削インサート１００Ｂの構成は、切削インサート１００の構成と異なっている。 However, in the cutting insert 100B, each of the plurality of divided pieces 21 does not have the first convex portion 26 and the second convex portion 27. In this respect, the configuration of the cutting insert 100B is different from the configuration of the cutting insert 100.
　切削インサート１００Ｂにおいては、刃先チップ２０が突出部１１を環状に取り囲むように配置されているため、基材１０が突出部１１を有しておらず、上面１０ｂの全面にわたって刃先チップ２０を取り付けなければならない場合と比較して、刃先チップ２０に使用される素材の量が低減される。 In the cutting insert 100B, since the cutting edge tip 20 is arranged so as to surround the protruding portion 11 in an annular shape, the base material 10 does not have the protruding portion 11, and the cutting edge tip 20 must be attached to the entire surface of the upper surface 10b. The amount of material used for the cutting edge tip 20 is reduced as compared to the case where it must be.
　また、切削インサート１００Ｂにおいては、貫通穴３０を形成するために刃先チップ２０に対する穴開け加工を行う必要がない。そのため、切削インサート１００Ｂによると、切削インサート１００Ａと比較して、製造コストを低減することができる。 Further, in the cutting insert 100B, it is not necessary to drill a hole in the cutting edge tip 20 in order to form the through hole 30. Therefore, according to the cutting insert 100B, the manufacturing cost can be reduced as compared with the cutting insert 100A.
　しかしながら、切削インサート１００Ｂにおいては、刃先チップ２０が複数の分割片２１に分割されているため、刃先チップ２０を基材１０にろう付けする際、溶融したろう材の表面張力により、複数の分割片２１の各々の間に隙間が形成されてしまうことがある。 However, in the cutting insert 100B, since the cutting edge tip 20 is divided into a plurality of divided pieces 21, when the cutting edge tip 20 is brazed to the base material 10, the surface tension of the molten brazing material causes the plurality of divided pieces. A gap may be formed between each of the 21.
　図９は、切削インサート１００の効果を説明するための模式図である。図９に示されるように、切削インサート１００においては、第１面１１ｂａが貫通穴３０とは反対側に向かって凸になっているため、ろう材が溶融した際、溶融したろう材の表面張力により、分割片２１ａが、第１面１１ｂａに沿って回転しようとする。 FIG. 9 is a schematic diagram for explaining the effect of the cutting insert 100. As shown in FIG. 9, in the cutting insert 100, since the first surface 11ba is convex toward the side opposite to the through hole 30, when the brazing filler metal is melted, the surface tension of the melted brazing filler metal is increased. As a result, the split piece 21a tries to rotate along the first surface 11ba.
　また、重心位置Ｐ５が分割片２１ａの長手方向において頂点Ｐ１から分割片２１ａの一方端側にずれているため、溶融したろう材の表面張力による分割片２１ａの回転は、第１凸部２６が第３面１１ｂｃに近づくとともに、第２凸部２７が第１面１１ｂａから離れるように回転しやすい（すなわち、図９中において反時計回りに回転しやすい）。同様にして、分割片２１ｂ～分割片２１ｄも、分割片２１ａと同一の方向に回転しやすい。 Further, since the center of gravity position P5 is displaced from the apex P1 to one end side of the divided piece 21a in the longitudinal direction of the divided piece 21a, the rotation of the divided piece 21a due to the surface tension of the molten brazing material is caused by the first convex portion 26. As it approaches the third surface 11bc, the second convex portion 27 tends to rotate away from the first surface 11ba (that is, it tends to rotate counterclockwise in FIG. 9). Similarly, the divided pieces 21b to 21d also tend to rotate in the same direction as the divided pieces 21a.
　しかしながら、分割片２１ａの第１凸部２６が第３面１１ｂｃとの間で分割片２１ｃの第２凸部２７を挟み込んでおり、分割片２１ｂの第１凸部２６が第４面１１ｂｄとの間で分割片２１ｄの第２凸部２７を挟み込んでいる。また、分割片２１ｃの第１凸部２６が第２面１１ｂｂとの間で分割片２１ｂの第２凸部２７を挟み込んでおり、分割片２１ｄの第１凸部２６が第１面１１ｂａとの間で分割片２１ａの第２凸部２７を挟み込んでいる。 However, the first convex portion 26 of the split piece 21a sandwiches the second convex portion 27 of the split piece 21c between the third surface 11bc and the first convex portion 26 of the split piece 21b with the fourth surface 11bd. The second convex portion 27 of the divided piece 21d is sandwiched between them. Further, the first convex portion 26 of the split piece 21c sandwiches the second convex portion 27 of the split piece 21b between the second surface 11bb and the first convex portion 26 of the split piece 21d with the first surface 11ba. The second convex portion 27 of the divided piece 21a is sandwiched between them.
　その結果、第２凸部２７が第３面１１ｂｃから離れようとする分割片２１ｃの回転は第１凸部２６が第３面１１ｂｃに近づこうとする分割片２１ａの回転により抑制され、第２凸部２７が第４面１１ｂｄから離れようとする分割片２１ｄの回転は第１凸部２６が第４面１１ｂｄに近づこうとする分割片２１ｂの回転により抑制される。 As a result, the rotation of the split piece 21c in which the second convex portion 27 tries to move away from the third surface 11bc is suppressed by the rotation of the split piece 21a in which the first convex portion 26 tries to approach the third surface 11bc, and the second convex portion 26. The rotation of the split piece 21d in which the portion 27 tends to move away from the fourth surface 11bd is suppressed by the rotation of the split piece 21b in which the first convex portion 26 tries to approach the fourth surface 11bd.
　同様に、第２凸部２７が第２面１１ｂｂから離れようとする分割片２１ｂの回転は第１凸部２６が第２面１１ｂｂに近づこうとする分割片２１ｃの回転により抑制され、第２凸部２７が第１面１１ｂａから離れようとする分割片２１ａの回転は第１凸部２６が第１面１１ｂａに近づこうとする分割片２１ｄの回転により抑制される。 Similarly, the rotation of the split piece 21b in which the second convex portion 27 tries to move away from the second surface 11bb is suppressed by the rotation of the split piece 21c in which the first convex portion 26 tries to approach the second surface 11bb, and the second convex portion 26 The rotation of the split piece 21a in which the portion 27 tends to move away from the first surface 11ba is suppressed by the rotation of the split piece 21d in which the first convex portion 26 tries to approach the first surface 11ba.
　このように、切削インサート１００によると、複数の分割片２１の各々の溶融したろう材の表面張力による回転の方向が同一になることにより、複数の分割片２１の回転が相互に抑制されるため、複数の分割片２１の各々の間に隙間が生じることが抑制される。 As described above, according to the cutting insert 100, the rotation of the plurality of divided pieces 21 is mutually suppressed by the same direction of rotation due to the surface tension of the molten brazing material of each of the plurality of divided pieces 21. , It is suppressed that a gap is generated between each of the plurality of divided pieces 21.
　また、切削インサート１００においては、切削インサート１００Ｂと同様に、刃先チップ２０に使用される素材の量を低減することができるとともに、貫通穴３０を形成するための加工コストを低減することができる。さらに、切削インサート１００においては、第１凸部２６に位置する側面２３と第１凸部２６に位置する上面２５との稜線を切れ刃として用いることができるため、切削インサート１００Ｂと比較して刃先チップ２０のより多くの部分を切れ刃として用いることができる。 Further, in the cutting insert 100, similarly to the cutting insert 100B, the amount of the material used for the cutting edge tip 20 can be reduced, and the processing cost for forming the through hole 30 can be reduced. Further, in the cutting insert 100, since the ridgeline between the side surface 23 located on the first convex portion 26 and the upper surface 25 located on the first convex portion 26 can be used as a cutting edge, the cutting edge is compared with the cutting insert 100B. More portions of the insert 20 can be used as cutting edges.
　切削インサート１００において、距離ＤＩＳ１が距離ＤＩＳ２よりも大きい場合、分割片２１の幅を狭くすることができるため、刃先チップ２０に用いられる素材の量をさらに低減することができる。 In the cutting insert 100, when the distance DIS1 is larger than the distance DIS2, the width of the split piece 21 can be narrowed, so that the amount of the material used for the cutting edge tip 20 can be further reduced.
　今回開示された実施の形態は全ての点で例示であって、制限的なものではないと考えられるべきである。本発明の範囲は、上記した実施の形態ではなく、請求の範囲によって示され、請求の範囲と均等の意味及び範囲内での全ての変更が含まれることが意図される。 It should be considered that the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims, not the embodiment described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.
　１００，１００Ａ，１００Ｂ　切削インサート、１０　基材、１０ａ　底面、１０ｂ　上面、１０ｂａ　第１辺、１０ｂｂ　第２辺、１０ｂｃ　第３辺、１０ｂｄ　第４辺、１０ｃ　側面、１１　突出部、１１ａ　上面、１１ｂ　側面、１１ｂａ　第１面、１１ｂｂ　第２面、１１ｂｃ　第３面、１１ｂｄ　第４面、２０　刃先チップ、２１，２１ａ，２１ｂ，２１ｃ，２１ｄ　分割片、２２，２３　側面、２４　底面、２５　上面、２６　第１凸部、２７　第２凸部、３０　貫通穴、Ｃ　中心、ＤＩＳ１，ＤＩＳ２　距離、Ｐ１，Ｐ２，Ｐ３，Ｐ４　頂点、Ｐ５，Ｐ６，Ｐ７，Ｐ８　重心位置、Ｓ１　準備工程、Ｓ２　ろう付け工程。 100, 100A, 100B cutting insert, 10 base material, 10a bottom surface, 10b top surface, 10ba 1st side, 10bb 2nd side, 10bb 3rd side, 10bd 4th side, 10c side surface, 11 protrusion, 11a top surface, 11b side surface , 11ba 1st surface, 11bb 2nd surface, 11bc 3rd surface, 11bd 4th surface, 20 cutting edge tip, 21,21a, 21b, 21c, 21d split piece, 22, 23 side surface, 24 bottom surface, 25 top surface, 26th 1 convex part, 27 2nd convex part, 30 through hole, C center, DIS1, DIS2 distance, P1, P2, P3, P4 vertex, P5, P6, P7, P8 center of gravity position, S1 preparation process, S2 brazing process.

Claims (4)

  1. 　基材と、
    　刃先チップとを備え、
    　前記基材は、前記基材の厚さ方向において、底面と、前記底面の反対面である上面とを有しており、
    　前記上面は、前記厚さ方向に沿って見た平面視において、複数の辺により構成される多角形形状を有しており、
    　前記上面には、前記厚さ方向に沿って前記底面とは反対側に突出する突出部が設けられており、
    　前記突出部には、前記基材を前記厚さ方向に沿って貫通している貫通穴が形成されており、
    　前記突出部は、前記上面に連なっている側面を有しており、
    　前記側面は、前記厚さ方向に沿って見た平面視において、前記貫通穴とは反対側に向かって凸の曲線により構成されており、
    　前記曲線は、前記複数の辺の各々との距離が最小となる位置において、複数の頂点を含み、
    　前記刃先チップは、前記突出部を環状に取り囲むように前記上面及び前記側面にろう付けされており、
    　前記刃先チップは、複数の分割片により構成されており、
    　前記複数の分割片の数は、前記複数の辺の数に等しく、
    　前記複数の分割片の長手方向の各々は、それぞれ、前記複数の辺の各々に沿っており、
    　前記複数の分割片の各々は、前記長手方向において、第１端と、前記第１端の反対側における端である第２端とを有しており、
    　前記複数の分割片の各々は、前記第１端において第１凸部を有するとともに、前記第２端において第２凸部を有しており、
    　前記複数の分割片のうちの１つの分割片の前記第１凸部は、前記複数の分割片のうちの前記１つの分割片と隣り合う別の分割片の前記第２凸部を前記側面との間に挟み込んでおり、
    　前記複数の分割片の重心位置の各々は、それぞれ、前記長手方向において、前記複数の頂点の各々とずれた位置にある、切削インサート。     With the base material
    Equipped with a cutting edge tip,
    The base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material.
    The upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction.
    The upper surface is provided with a protruding portion that protrudes from the bottom surface in the thickness direction.
    A through hole is formed in the protrusion so as to penetrate the base material along the thickness direction.
    The protrusion has a side surface that is continuous with the upper surface.
    The side surface is formed by a curved line that is convex toward the side opposite to the through hole in a plan view seen along the thickness direction.
    The curve contains a plurality of vertices at a position where the distance from each of the plurality of sides is minimized.
    The cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape.
    The cutting edge tip is composed of a plurality of divided pieces.
    The number of the plurality of divided pieces is equal to the number of the plurality of sides,
    Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides.
    Each of the plurality of divided pieces has a first end in the longitudinal direction and a second end which is an end on the opposite side of the first end.
    Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end.
    The first convex portion of one of the plurality of divided pieces has the second convex portion of another divided piece adjacent to the one divided piece of the plurality of divided pieces as the side surface. It is sandwiched between
    A cutting insert in which each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
  2. 　前記曲線は、複数の部分円弧により構成されており、
    　前記複数の部分円弧の各々は、それぞれ、前記複数の辺の各々に対向しており、
    　前記厚さ方向に沿って見た平面視において、前記突出部の角と前記貫通穴の中心との間の距離は、前記複数の頂点の各々と前記中心との間の距離よりも大きい、請求項１に記載の切削インサート。     The curve is composed of a plurality of partial arcs.
    Each of the plurality of partial arcs faces each of the plurality of sides.
    Claimed that the distance between the angle of the protrusion and the center of the through hole is greater than the distance between each of the plurality of vertices and the center in a plan view along the thickness direction. Item 1. The cutting insert according to Item 1.
  3. 　前記刃先チップは、立方晶窒化硼素焼結体又は多結晶ダイヤモンド焼結体により形成されている、請求項１又は請求項２に記載の切削インサート。 The cutting insert according to claim 1 or 2, wherein the cutting edge tip is formed of a cubic boron nitride sintered body or a polycrystalline diamond sintered body.
  4. 　基材及び刃先チップを準備する工程と、
    　前記刃先チップを前記基材にろう付けする工程とを備え、
    　前記基材は、前記基材の厚さ方向において、底面と、前記底面の反対面である上面とを有しており、
    　前記上面は、前記厚さ方向に沿って見た平面視において、複数の辺により構成される多角形形状を有しており、
    　前記上面には、前記厚さ方向に沿って前記底面とは反対側に突出する突出部が設けられており、
    　前記突出部には、前記厚さ方向に沿って前記基材を貫通している貫通穴が形成されており、
    　前記突出部は、前記上面に連なっている側面を有しており、
    　前記側面は、前記厚さ方向に沿って見た平面視において、前記貫通穴とは反対側に向かって凸の曲線により構成されており、
    　前記曲線は、前記複数の辺の各々との距離が最小となる位置において、複数の頂点を含み、
    　前記刃先チップは、前記突出部を環状に取り囲むように前記上面及び前記側面にろう付けされ、
    　前記刃先チップは、複数の分割片により構成されており、
    　前記複数の分割片の数は、前記複数の辺の数に等しく、
    　前記複数の分割片の長手方向の各々は、それぞれ、前記複数の辺の各々に沿っており、
    　前記複数の分割片の各々は、前記長手方向において、第１端と、前記第１端の反対側における端である第２端とを有し、
    　前記複数の分割片の各々は、前記第１端において第１凸部を有するとともに、前記第２端において第２凸部を有しており、
    　前記複数の分割片のうちの１つの分割片の前記第１凸部は、前記複数の分割片のうちの前記１つの分割片と隣り合う別の分割片の前記第２凸部を前記側面との間に挟み込んでおり、
    　前記複数の分割片の重心位置の各々は、それぞれ、前記長手方向において、前記複数の頂点の各々とずれた位置にある、切削インサートの製造方法。     The process of preparing the base material and the cutting edge tip,
    A step of brazing the cutting edge tip to the base material is provided.
    The base material has a bottom surface and an upper surface opposite to the bottom surface in the thickness direction of the base material.
    The upper surface has a polygonal shape composed of a plurality of sides in a plan view along the thickness direction.
    The upper surface is provided with a protruding portion that protrudes from the bottom surface in the thickness direction.
    A through hole penetrating the base material is formed in the protrusion along the thickness direction.
    The protrusion has a side surface that is continuous with the upper surface.
    The side surface is formed by a curved line that is convex toward the side opposite to the through hole in a plan view seen along the thickness direction.
    The curve contains a plurality of vertices at a position where the distance from each of the plurality of sides is minimized.
    The cutting edge tip is brazed to the upper surface and the side surface so as to surround the protrusion in an annular shape.
    The cutting edge tip is composed of a plurality of divided pieces.
    The number of the plurality of divided pieces is equal to the number of the plurality of sides,
    Each of the plurality of pieces in the longitudinal direction is along each of the plurality of sides.
    Each of the plurality of divided pieces has a first end in the longitudinal direction and a second end which is an end on the opposite side of the first end.
    Each of the plurality of divided pieces has a first convex portion at the first end and a second convex portion at the second end.
    The first convex portion of one of the plurality of divided pieces has the second convex portion of another divided piece adjacent to the one divided piece of the plurality of divided pieces as the side surface. It is sandwiched between
    A method for manufacturing a cutting insert, wherein each of the positions of the center of gravity of the plurality of divided pieces is located at a position deviated from each of the plurality of vertices in the longitudinal direction.
PCT/JP2020/023736 2020-06-17 2020-06-17 Cutting insert and method for manufacturing cutting insert WO2021255852A1 (en)

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PCT/JP2020/023736 WO2021255852A1 (en) 2020-06-17 2020-06-17 Cutting insert and method for manufacturing cutting insert
EP20940838.4A EP4169663B1 (en) 2020-06-17 2020-06-17 Cutting insert and method of manufacturing cutting insert
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JPS58120406A (en) * 1982-01-14 1983-07-18 Nippon Oil & Fats Co Ltd High hardness sintered tool
JPS6053404U (en) 1983-09-19 1985-04-15 住友電気工業株式会社 Cutting tools
JPH10118824A (en) * 1996-10-24 1998-05-12 Fuji Seiko Kk Vertical type tip and milling cutter therewith
JP2008501539A (en) * 2004-06-02 2008-01-24 サンドビック インテレクチュアル プロパティー アクティエボラーグ Indexable cutting insert and manufacturing method thereof
JP2009529432A (en) * 2006-03-06 2009-08-20 ダイヤモンド イノベーションズ、インク． Cutting tool insert with molded insert body
JP2013530844A (en) * 2010-07-13 2013-08-01 エレメント シックス リミテッド Indexing type cutter insert, molded article for indexing type cutter insert and manufacturing method thereof
JP2014121772A (en) * 2012-11-22 2014-07-03 Mitsubishi Materials Corp Cutting insert and cutting insert manufacturing method

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JPS5652604U (en) * 1979-09-27 1981-05-09

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58120406A (en) * 1982-01-14 1983-07-18 Nippon Oil & Fats Co Ltd High hardness sintered tool
JPS6053404U (en) 1983-09-19 1985-04-15 住友電気工業株式会社 Cutting tools
JPH10118824A (en) * 1996-10-24 1998-05-12 Fuji Seiko Kk Vertical type tip and milling cutter therewith
JP2008501539A (en) * 2004-06-02 2008-01-24 サンドビック インテレクチュアル プロパティー アクティエボラーグ Indexable cutting insert and manufacturing method thereof
JP2009529432A (en) * 2006-03-06 2009-08-20 ダイヤモンド イノベーションズ、インク． Cutting tool insert with molded insert body
JP2013530844A (en) * 2010-07-13 2013-08-01 エレメント シックス リミテッド Indexing type cutter insert, molded article for indexing type cutter insert and manufacturing method thereof
JP2014121772A (en) * 2012-11-22 2014-07-03 Mitsubishi Materials Corp Cutting insert and cutting insert manufacturing method

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EP4169663A1 (en) 2023-04-26
CN115835938A (en) 2023-03-21

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